聚羟基丁酸酯遥爪聚合物的合成

Synthesis of Hydroxyl-Terminated Poly( hydroxybutyrate) Telechelic Polymers

以二乙二醇二甲醚为溶剂,二月桂酸二丁基锡为催化剂,合成了含端羟基的聚羟基丁酸酯遥爪聚合物（PHB-diol）.通过核磁、红外分析、凝胶渗透色谱等测定聚合物的结构和数均摩尔质量,探讨反应时间、催化剂用量对遥爪聚合物数均摩尔质量的影响,结果发现,在反应初始4h,聚合物数均摩尔质量下降显著,当反应进行到8h,下降趋势减缓;二月桂酸二丁基锡用量为反应原料总质量的1％时,催化效果最理想.PHB-diol的结构与聚羟基丁酸酯（PHB）原料结构一致,热稳定性和结晶度有所下降.采用醋酐-吡啶法测量端羟基的含量,羟基与聚合物的物质的量比为1.36：1-1.99：1.

A series of hydroxyl-terminated poly （hydroxybutyrate） telechelic polymers （PHB-diol） were synthesized with diethylene glycol dimethyl ether as the solvent and dibutyltin dilaurate as the catalyst. The chemical structure, molecular weight and its distribution were systematically characterized by nuclear magnetic resonance spectrum, Fourier transorm infrared spectroscopy and gel permeation chromatography. The effects of reaction time and catalyst amount on the molecular weight of PHB-diol were studied. The results indicate that the molecular weight of PHB-diol decreased significantly in the initial 4 h and became to decline slowly when the reaction lasted 8 h. The optimum dosage of dibutyltin dilaurate is 1% of total mass. The structure of PHB-diol is accord with that of PHB, and thermal stability and crystallinity decrease compared with raw materials. The content of hydroxyl-terminated was measured via acetic anhydride-pyridine method, and the molar ratio of hydroxyl to polymer is from 1.36 ： 1 to 1.99 ： 1.